The purpose of this project is to investigate the molecular structure of collagen, elastin and proteoglycans, and to correlate the results obtained with function. The areas of present interest are: 1. Structure of the terminal regions in the collagen trimer. The aromatic regions of proton magnetic resonance spectra are being used to probe the structure and function of the non-helical portions of the molecule. 2. The structure of elastin. Nuclear magnetic resonance is being used to determine the mobility of elastin chains and elucidate the mechanism of elasticity. 3. The structure of proteoglycans. C13 magnetic resonance is being used to measure the molecular mobility of the polysaccharides and protein chains in cartilage to elucidate the molecular structure and interactions in the tissue.